He never stays up late at night, _____ he—_________. He usually does his homework till midnight.

In many countries, children must go to school ___________ the age of 5 and 16.

Sorry, I can’t workout this problem. —Try again,please. It’s only ______ difficult.

He didn’t work hard and_________ he couldn’t finish his task on time[ ]

Hot _______the night air was, we slept deeply because we were so tired after the long journey.[ ]